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https://github.com/jonathanpeppers/android-nativeaot
A .NET 8, NativeAOT example on Android
https://github.com/jonathanpeppers/android-nativeaot
android csharp dotnet nativeaot
Last synced: 3 months ago
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A .NET 8, NativeAOT example on Android
- Host: GitHub
- URL: https://github.com/jonathanpeppers/android-nativeaot
- Owner: jonathanpeppers
- License: mit
- Created: 2023-12-15T17:59:27.000Z (about 1 year ago)
- Default Branch: main
- Last Pushed: 2024-05-01T18:44:30.000Z (9 months ago)
- Last Synced: 2024-05-02T05:51:01.545Z (9 months ago)
- Topics: android, csharp, dotnet, nativeaot
- Language: C#
- Homepage:
- Size: 24.7 MB
- Stars: 45
- Watchers: 2
- Forks: 4
- Open Issues: 1
-
Metadata Files:
- Readme: README.md
- License: LICENSE
Awesome Lists containing this project
README
# Android-NativeAOT
A .NET 8, NativeAOT example on Android.
## Getting started
Configure your environment: the following environment variables are required:
* `ANDROID_NDK_HOME`: The path to an Android NDK installation.
* `ANDROID_HOME`: The path to an Android SDK installation.
Build the project:
```console
dotnet build
dotnet publish DotNet/libdotnet.csproj
(cd Native && ./gradlew assembleRelease)
```
Install the app:
```console
$ANDROID_HOME/platform-tools/adb install Native/app/build/outputs/apk/release/app-release.apk
```
Run the app:
```console
$ANDROID_HOME/platform-tools/adb shell am start com.jonathanpeppers.nativeaot/android.app.NativeActivity
```
## Example using SkiaSharp
This sample has a C++ Android Studio project:
* Uses [Native Activity](https://developer.android.com/ndk/samples/sample_na)
* No Java/Kotlin code
* Configures OpenGL
* Calls into C# / managed code
* Managed code uses SkiaSharp for rendering a random Skia shader
* Tap input randomly changes the shader
Some screenshots of the Skia content:
(Note these look completely smooth on a Pixel 5, I just tried to snap quick gifs with Vysor)
The C# side is a:
* .NET 8 class library
* Built with RID `linux-bionic-arm64`
* Uses the SkiaSharp NuGet package, as one would.
* Used a nightly build of SkiaSharp, as I wanted a feature from Skia 3.0
## App Size
The release `.apk` file of the SkiaSharp sample is ~4.26 MB
A breakdown of the files inside:
```
> 7z l app-release.apk
Date Time Attr Size Compressed Name
------------------- ----- ------------ ------------ ------------------------
1981-01-01 01:01:02 ..... 56 52 META-INF\com\android\build\gradle\app-metadata.properties
1981-01-01 01:01:02 ..... 1524 753 classes.dex
1981-01-01 01:01:02 ..... 8525024 3733033 lib\arm64-v8a\libSkiaSharp.so
1981-01-01 01:01:02 ..... 1070792 473191 lib\arm64-v8a\libdotnet.so
1981-01-01 01:01:02 ..... 19504 6869 lib\arm64-v8a\libnativeaot.so
1981-01-01 01:01:02 ..... 2376 867 AndroidManifest.xml
1981-01-01 01:01:02 ..... 7778 7778 res\-6.webp
1981-01-01 01:01:02 ..... 548 239 res\0K.xml
1981-01-01 01:01:02 ..... 5696 987 res\0w.xml
1981-01-01 01:01:02 ..... 788 347 res\9s.xml
1981-01-01 01:01:02 ..... 548 239 res\BW.xml
1981-01-01 01:01:02 ..... 1404 1404 res\MO.webp
1981-01-01 01:01:02 ..... 1572 703 res\PF.xml
1981-01-01 01:01:02 ..... 2884 2884 res\Sn.webp
1981-01-01 01:01:02 ..... 982 982 res\d2.webp
1981-01-01 01:01:02 ..... 2898 2898 res\fq.webp
1981-01-01 01:01:02 ..... 5914 5914 res\j_.webp
1981-01-01 01:01:02 ..... 1900 1900 res\qs.webp
1981-01-01 01:01:02 ..... 3844 3844 res\sK.webp
1981-01-01 01:01:02 ..... 3918 3918 res\u5.webp
1981-01-01 01:01:02 ..... 1772 1772 res\yw.webp
1981-01-01 01:01:02 ..... 2036 2036 resources.arsc
1981-01-01 01:01:02 ..... 2085 1122 META-INF\CERT.SF
1981-01-01 01:01:02 ..... 1167 1021 META-INF\CERT.RSA
1981-01-01 01:01:02 ..... 2011 1046 META-INF\MANIFEST.MF
------------------- ----- ------------ ------------ ------------------------
1981-01-01 01:01:02 9669021 4255799 25 files
```
`libdotnet.so` is ~1.07 MB, and `libSkiaSharp.so` is ~8.5MB!
If we reduce this to a "Hello World" example:
* `hello.apk` is ~430 KB!
* `libdotnet.so` (uncompressed) is ~821 KB!
## Startup Time
The average of 10 runs on a Pixel 5 of the SkiaSharp sample:
```log
Average(ms): 121
Std Err(ms): 3.29983164553722
Std Dev(ms): 10.434983894999
```
Average of 10 runs on a Pixel 5 of the "Hello World" example:
```log
Average(ms): 120.9
Std Err(ms): 2.97937353594118
Std Dev(ms): 9.42160637400367
```
They might be effectively the same.
For comparison (as of .NET 8), a `dotnet new android` app is about ~180ms on a
Pixel 5, and `dotnet new maui` is about ~560ms.
Source: https://github.com/jonathanpeppers/maui-profiling
## "Hello World" Example
See the [HelloWorld](https://github.com/jonathanpeppers/Android-NativeAOT/tree/HelloWorld) branch.
I had this managed code:
```csharp
[UnmanagedCallersOnly(EntryPoint = "ManagedAdd")]
public static int ManagedAdd(int x, int y) => x + y;
```
I created a C++ Android project using NativeActivity, and I called the managed
code from C++:
```c++
// in dotnet.h
extern "C" int ManagedAdd(int x, int y);
// in native-lib.cpp
int result = ManagedAdd(1, 2);
__android_log_print (ANDROID_LOG_INFO, TAG, "ManagedAdd(1, 2) returned: %i", result);
```
Results in the message:
```log
01-31 11:42:44.545 28239 28259 I NATIVE : Entering android_main
01-31 11:42:44.550 28239 28259 I NATIVE : ManagedAdd(1, 2) returned: 3
```
See [DotNet/README.md](DotNet/README.md) on how to build `libdotnet.so`.
## Notes
`Console.WriteLine()` doesn't work because it basically just writes to Unix stdout. stdout does not appear in `adb logcat` output, as you have to call `__android_log_print` instead.
This was an interesting example, to start a thread that processes stdout and calls the appropriate Android API:
* https://codelab.wordpress.com/2014/11/03/how-to-use-standard-output-streams-for-logging-in-android-apps/
Instead, we can p/invoke into:
```csharp
[DllImport("log", EntryPoint = "__android_log_print", CallingConvention = CallingConvention.Cdecl)]
public static extern int LogPrint(LogPriority priority, string tag, string format);
```